Means for regulating the depth a submarine device tows through water



March 15, 1960 J. c. MCCORMICK MEANS FOR REGULATING THE DEPTH A SUBMARINE. v DEVICE 'rows THROUGH WATER Filed Aug. 51, 1953 2 Sheets-Sheet l INVNTOR JESSE C. MpflORMICK ATTGRNEYS M CORMICK MEANS FOR REGULATING THE DEPTH A SUBMARINE March 15, 1960 DEVICE TOWS THROUGH WATER Filed Aug. 31, 1953 2 Sheets-Sheet 2 QCEAN FLOOR Fig.5

INVENTOR BY m )1 6.242:-

ATTORNEYS Saes MEANS FOR REGULATING THE DEPTH A SUB- MARINE DEVICE TOWS THROUGH WATER The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to a submarine device adapted to be towed through a seaway and more particularly'to such a device which will, when towed through a body of water, seek and maintain itself at a predetermined constant distance above the bottom irrespective of the depth of the water.

It is frequently desirable to transport instruments at a known distance above the ocean floor for the purpose of locating or detecting objects thereon such as mines and the like. Various arrangements have been proposed for accomplishing this purpose, but they have in general been unwieldy, unreliable or quite expensive.

In accordance with this invention the depth at which a dirigible submarine device tows through a seaway is controlled by means responsive to the difference between the pressure of flotation of the device and the pressure at the bottom of the seaway. To this end a sled adapted when towed to, slide along the ocean floor is provided with means for continuously sensing the ambient hydrostatic pressure and translating it into a force, preferably in the form of air pressure, having a magnitude corresponding thereto. This force representative of the hydrostatic pressure at the bottom is transmitted to the control mechanism of a towed submarine device for regulating the depth at which it rides through the water so that at all times it follows a path parallel to the ocean floor 'and vertically spaced therefrom by a distance predetermined in the original setting of its control mechanism. In the preferred embodiment of the invention to be described in detail, the control mechanism is pneumatically actuated by means of a metal bellows one side of which is exposed to the water of flotation, i.e., the pressure at-the submarine device, and the other side of which is subjected to an air pressure corresponding tO-the-depth of the ocean by means of'a hose connected to an air filled flexible member carried in a free-flooding section of the sled. The control mechanism may comprise elevator fins (sometimes referred to as divinganother pressure responsive device is provided in a free- ;flooding section of the submarine device and connected to an instrument panel on the towing vessel for indicating the position of the submarine device in terms of depth below the surface. The instrument panel also carries a pressure gauge connected to the control force developed in th'e'sled for indicating the ocean depth and another atent gauge responsive to the difference between the pressures at the submarine device and the sled for indicating the position of the submarine device in terms of distance above the ocean floor.

An object of the present invention is the provision of a free floating submarine device which will maintain itself at a fixed distance above the floor of a seaway through which it is towed.

Another object of the invention is the provision of means for sensing the depth of the ocean floor and for transmitting this information in the form of a control force to the submarine device.

A still further object of the invention is the provision of an arrangement for indicating at the towing vessel the depth of the seaway and the distance the submarine device is riding above the bottom.

The exact nature of the invention as well as other obejcts and advantages thereof will be readily apparent from the following description of a preferred embodiment when read in connection with the accompanying drawings in which:

Fig. 1 shows in perspective a submarine device and its attendant control sled being. towed through a seaway;

Fig. 2 shows diagrammatically the control arrangement employed; and,

Fig. 3 shows a modification of the control wherein no information is transmitted to the towing vessel.

Referring now to the drawings wherein like reference characters designate like parts throughout the several views, there is shown in Fig. 1 a submarine device 11 having a streamlined shape and adapted to be towed through a seaway by a surface vessel 12 by means of a towing cable 13 connected to a towing bail 14 pivotally secured to the submarine device 11 in any suitable manner as by trunnions 15. The submarine device 11 is preferably provided with three compartments longitudinally alined and separated by bulkheads 16 and 17, a

the center compartment between the two bulkheads 16 and 17 being air and water tight and available for containing any instrument or detectors suitable to perform the mission for which the device 11 is being towed, such as indicating the presence of a mine 36. The forward compartment occupying the nose of the device 11 is rendered free flooding, as by openings 18, and is provided with a pressure sensitive means such as a flexible balloon 19 containing a gas such as air and connected through a hose 21 to an instrument panel 22 carried on board the towing vessel 12.

The rear compartment in the submarine device 11 behind the bulkhead 17 is provided with a pneumatically operative device 23 here shown as a bellows responsive to pressure differences for moving a reachrod 24 secured in operating relation to elevator fins 25 for controlling the angie they make with the horizontal axis of the device 11. The effective length of the reachrod 24 is preferably adjustable, as by the provision of a turnbuckle 20, for altering the coupling between the bellows device 23 and the depth controlling elevator fins 25. The bellows 23 responsive to pressure differences will be described at the ocean floor through a hose 27 leading to the instrument panel 22 on the towing vessel 12 and back through a hose 28 ton pressure responsive device such as an air filled, flexible balloon 29 provided in a sled 31 and exposed to hydrostatic pressure by means of suitable openings 32 for free flooding the chamber in the sled 31 containing theballoon 29. The sled 31 is preferably streamlined to reduce the possibility of it fouling on the ocean floor as it is towed along by means of a suitable cable 33 secured to the towing vessel 12. In accordance with usual practice the hose 28 is married to the towing cable '53 by suitable bands 34. Similarly, marriage bands 35 secure the hoses 21 and 2-7 to the towing cable 13.

The submarine device 11 is provided with fixed horizontally extending fins 37 to the after ends of which is rotatably secured a shaft 38 on which the elevator fins 25 are mounted. The shaft 38 also carries a bell crank 3i) to which the reachrod 24 is connected so that longitudinal movement imparted to the reachrod 24 by the bellows device 23 is translated into angular movement of the elevator fins 25. Vertically dependent fins 39 rigidly secured to the bottom side of the submargine device 11 serve to minimize roll and to provide ballast for maintaining the device 11 on an even keel and otherwise stabilizing its towing properties;

To facilitate streaming and recovery, the submarine device 11 is preferably designed to have positive buoyancy sufiicient to rise to the surface when not being towed. Contrariwise, the sled 31 has negative buoyancy sufficient to assure its riding on the ocean floor under towing conditions.

The manner in which the system functions is more clearly shown in Fig. 2 which is a schematic view of the operating parts of the control and indicating systems. As here shown, the bellows device 23 comprises a cup-shaped metal bellows 40 having its closed end extending into an enclosing airtight housing 41 and having its open end exposed to the water of flotation. The interior of the housing 41 is connected through the hose 27, a manifold 42, and the hose 28 to the control pickup balloon 29 in the sled 31, thereby subjecting the closed end of the bellows 40 to the pressure sensed by the balloon 29 at the ocean floor. A pressure gauge 43 connected to the manifold 42 measures the pressure in the control pickup balloon 29 and may be calibrated to indicate the depth of the ocean in feet. Another pressure gauge 44 connected through a conventional T-fitting 45 to the hose 21 measures the pressure in the balloon 19 and may be calibrated to indicate in feet the depth of the submarine device 11. A differential pressure gauge 46 connected both to the manifold 42 and to the T-fitting 45, measures pressure differences and may be calibrated to indicate in feet the distance D the submarine device 11 is above the ocean floor. The three gauges 43, 44 and 46 are preferably mounted in the instrument panel 22 on board the towing vessel 12 so that operating conditions are at all times available to personnel on board the vessel 12.

For conducting a towing operation the closed air systems shown in Fig. 2 are precharged with air. Upon streaming the gear the sled 31 sinks to the bottom thereby subjecting the enclosed end of the bellows 40 to the pressure at the ocean floor. The submarine device 11 being slightly buoyant does not sink and thus the pressure difference on opposite sides of the bellows 40 is greater than the predetermined difference selected for stable operation and the bellows 40 moves to change the angle of the elevator fins 25 so that the submarine device 11 angles down in the water. As the device 11 increases in depth the hydrostatic pressure increases on the open end of the bellows 40 thereby gradually decreasing the angle of the elevator fins 25 until at a distance D determined by the original setting of the coupling between the elevator fins 25 and the bellows 4% the submarine device reaches a stable condition. Thereafter, any change in water depth experienced by the sled 31 will disturb the pressure difference acting on the bellows 4t? and the resulting movement of the bellows 40 will correspondingly alter the angle of the elevator fins 25 to maintain the submarine device 11 at substantially the distance D above the ocean fioor. To compensate for the small time interval required for the depth regulating mechanism of the device to respond to received pressure changes, the gear is streamed so that the sled 31 carrying the control pickup device 29 is towed slightly in advance of the submarine device 11.

In the modification schematically shown in Fig. 3 the control pickup balloon 29 in the bottom-riding sled 31 is connected through a host 47 directly to the bellows enclosing chamber 41 rather than via the instrument panel 22 on board the towing vessel 12 as shown in the preferred embodiment described above. This embodiment, shown in Fig. 3, functions to maintain the submarine device 11 at the distance D above the ocean floor in the manner already described and provides the advantage of requiring a very small length of hose. However, in many cases this advantage is small compared to the disadvantages arising from thegreatly increased hazard of the hose 4'] being fouled and from the lack of information on board the towing vessel 12 regarding performance. It will be appreciated that the hose 47 has sufiicient tensile strength to resist parting during streaming and until the control has a chance to function.

Inasmuch as the submarine device 11 is designed to ride at an even keel only when the pressure on the out side of the bellows 40 exceeds by a given amount the pressure to which the inside of the bellows 40 is subjected, it will be evident that failure due to breaking, or otherwise, of the air line between the control pickup balloon 29 and the bellows 40 will decrease this pressure difference and the submarine device 11 will rise to the surface.

It is to be understood that while the distance D at which the device 11 rides above the ocean fioor depends primarily upon the characteristics of the bellows device 23 and its coupling to the elevator fins 25, the control system is slightly sensitive to changes in towing speed and in water depth, the distance D varying inversely with speed and directly with water depth.

It will be evident that a plurality of submarine devices 11 may be simultaneously controlled by a single control pickup sled 31 and that by suitable individual adjustment 1 the couplings between the bellows device 23 and the elevator fins 25 on the several devices 11 they can be made to tow at different levels.

From the foregoing description it will be appreciated that the present invention provides an underwater vehicle which can be towed to carry instrumentation, detectors, or other types of gear at a desired distance above the bottom of a seaway. The means for actuating the elevator fins 25 has been shown as comprising a bellows device, but it will be obvious that any other suitable arrangement may be employed for translating pressure differences into mechanical movement of the elevator fins 25. Other arrangements and modifications will be apparent to those skilled in the art without departing from the spirit of the invention, the scope of which is pointed out in the appended claims.

Having thus described the invention, what is claimed as new and desired to be protected by Letters Patent of the United States is:

1. in a system for the control of a dirigible submarine vehicle towed through a seaway, elevator fins carried by said vehicle and adjustable to regulate the depth at which said vehicle rides in the seaway, means for deriving a pressure corresponding to the depth of the seaway, a spring biased diaphragm having one side subjected to the pressure of flotation of said vehicle and having its other side subjected to said derived pressure, and coupling means between said diaphragm and the elevator fins for adjusting said fins in accordance with the pressure difference to which said diaphragm is subjected, the coupling means being so adjusted that for a preselected pressure difference the elevator fins are adjusted to the position where said vehicle rides at an even keel, whereby when towed through a seaway the submarine vehicle follows a path parallel to the floor of the seaway and spaced therefrom by a distancedeterjmined by the pressure difierence selected'in adjusting the couplingmeans.

2. In a control system for a towed submarine device having means adjustable for regulating the depth at which said device tows through a seaway, a pilot sled having a free-flooding compartment and adapted when towed through a seaway to slide along the bottom thereof, an airfilled elastic container in said free-flooding compartment, pressure difference responsive means subjected to the pressure of flotation of the submarine device and tothe pressure at the bottom of the seaway as sensed by said elastic container, and means controlled by the pressure difierence responsive means for controlling the adjustment of said depth regulating means, whereby when the submarine device and the pilot sled are towed through a seaway the submarine device tows at a substantially constant distance above the bottom.

' depth regulating means, a vessel connected in towing relation to the submarine device and to the pilot sled, a depth indicating gauge mounted on the vessel and connected to said elastic container, and a differential pressure gauge mounted on the vessel and subjected to the pressure of flotation of the submarine device and to the pressure sensed by said elastic container for indicating the distance 7 the submarinedevice is above the bottom of the seaway.

4. In combination with a submarine device having elevator fins angularly adjustable for regulating the depth at which said device tows through a seaway, pressure difierence responsive means having a part movable in accordance with variations in pressure 'dilference, means for subjecting said responsive means to the difference between the pressure of flotation of the submarine device and the pressure at the bottom of the seaway, whereby the position of said movable part corresponds to the distance the submarine device is above the bottom, and linkage means driven by said movable part for correspondingly adjusting the angle of the elevator fins, the linkage means being such that the elevator fins are adjusted to the angle required for level towing when said movable part occupies the position corresponding to the distance above the bottom it is desired for the submarine device to tow.

References Citedin the file of this patent UNITED STATES PATENTS 2,359,366 Katcher et al. Oct. 3, 1944 2,589,312 Wilcoxon Mar. 18, 1952 2,632,150 Silverman et al Mar. 17, 1953 2,729,910 Fryklund Jan. 10, 1956 2,751,703 Kietz et al. June 26, 1956 

